The present invention relates to a method for making decorative emblems, plaques, panels, etc., which have a cured plastic layer over a decorative surface and, more particularly, it relates to a method for flow coating a fluent plastic material onto a decorative substrate to give a uniform thickness coated substrate from which emblems, plaques, or panels are formed.
Decorative plaques and emblems are widely used throughout a number of industries, including the automotive and appliance fields. In the past, a colored vitreous frit was flowed into a bronze substrate and fired at 1250.degree. F. The glass-like vitreous enamel served to beautify the product and protect the decorative substrate from weathering should the plaque or emblem be exposed to the environment.
Today, plastics are primarily used for producing such plaques and emblems. For example, in Loew (U.S. Pat. No. 3,654,062), there is disclosed a process for injection molding a decorative Mylar facing sheet over a vinyl plastic body. The plaque is coated with a layer of protective varnish on the outer surface of the facing sheet. Gits, U.S. Pat. No. 3,246,066, is similar in that male and female molds are used to form a cavity into which a decorative foil is placed and into which a clear plastic material is injected. Prior to injecting a clear plastic material against the front face of the foil, the foil is precoated. Other molding processes, such as compression molding (either one or two shot), are also well known in the art. See for instance, U.S. Pat. Nos. 2,244,565; 2,931,119; 3,075,249; and 3,114,597.
In my U.S. Pat. No. 4,100,010, there is disclosed an improved process for producing decorative emblems. That process involves casting a plastic material onto decorative foil shapes to form a meniscus which when cured gives a lens effect to the top surface of the foil shape. A problem with that process is that despite an ability to vary the size and shape, it is not practical to later conform the as-cast emblem to non-planar surfaces.
Another problem is that the foil shapes are cast individually and the manufacturing process can as a result be too cumbersome and costly for some purposes. Accordingly, the need exists for yet another improved process for producing decorative emblems which is less expensive, more efficient and which yields a product which can be formed to different three-dimensional shapes if desired.
The present invention meets that need by utilizing a flow coating process to apply a clear plastic material to a decorative substrate from which individual emblems and plaques may then be stamped and shaped. Of course, flow coating per se is known in a number of areas. My U.S. Pat. No. 4,034,708 discloses such a process for coating glass containers. As another example, U.S. Pat. Nos. 3,875,893 to Riley and 3,431,889 to Fraatz both disclose flow-coating processes using multiple orifices to lay down a thin film onto a flat surface. But Fraatz and Riley do not relate to emblem or plaque manufacturing processes where a clear plastic is applied to a decorative substrate.
It should also be noted that Hansen in U.S. Pat. No. 3,725,112 mentions flow coating as one of the possible methods for producing his coated or encapsulated substrates. That patent discloses applying a protective low-glare, uniformly textured, transparent, polymeric coating to a substrate such as wood, steel, hardboard, aluminum and the like. Still, the intent of Hansen is to produce textured films having a low-glare surface and not to produce decorative emblems of the type contemplated by the present invention.
Therefore, the need still remains for a method for flow coating clear plastic materials onto a decorative substrate to economically and efficiently produce decorative emblems, plaques, panels, etc.